184 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



Arizona-California, Yuma Project. — The diversion of the waters 

 of Colorado River into two canals, one on each side of the river, 

 is accomplished by means of Laguna Dam, a structure of the Indian 

 weir t3^pe, about 10 miles northeast of Yuma, Ariz. This dam was 

 completed in March, 1909. It is about 19 feet high, 4,780 feet long, 

 and 260 feet wide up and down stream (pi. 4. fig. 1). By a unique 

 arrangement at the headgates of the canals the waters of this muddy 

 stream are drawn off comparatively clear. The distribution system 

 consists of 100 miles of canals. A complete system of levees with a 

 length of 73{y miles has been constructed to protect the bottom lands 

 from overflow, and a pumping system will be utilized to remove the 

 surplus waters from the low-lying areas. 



On the Indian reservation on the California side of the river 173 

 farm units were opened to entry on March 1, 1910, and during 1910 

 many of the entrymen cleared and leveled their farms. The cost 

 of the water right is $55, payable in not more than 10 annual install- 

 ments, with an annual charge of $1 for operation and maintenance. 

 There is also a charge of $10 as the price of the Indian lands, payable 

 in not more than 10 annual installments. 



The bottom lands comprise 17,000 acres in the Yuma Indian Reser- 

 vation in California, 20,000 acres in the Gila River Valley in Ari- 

 zona, and 53,000 acres in Colorado River Valley in Arizona. When 

 the system is extended to include the mesa or table lands south of 

 Yuma and east of the bottom lands in Arizona, about 40,000 acres 

 of practically frostless land will be available for the cultivation of 

 oranges, lemons, grapefruit, limes, olives, vegetables, etc. 



The soil of the lowlands is a rich, alluvial deposit and produces 

 very heavy crops when water is applied. Alfalfa, grains, vegetables, 

 sugar beets, nuts, melons, fruits, cotton, cane, corn, etc., are grown. 



The watershed area is 160,000 square miles and the estimated an- 

 nual run-off is 15,400,000 acre-feet. The lands lie at an elevation of 

 100 to 300 feet above sea level, and the temperature ranges from 22° 

 to 118° above zero. 



California, Orland project. — The reclamation of 14,000 acres of 

 land lying about 90 miles north of Sacramento is involved in this 

 project. The lands when watered are fertile, although their use for 

 many years for wheat growing has deteriorated them for ordinary 

 agriculture. The soil is a gravelly loam, and with irrigation and 

 the prevailing climatic conditions it has been demonstrated that the 

 land is excellent for the production of alfalfa, nuts, including the 

 almond and English walnut, and both citrus and deciduous fruits. 

 The general elevation is from 175 to 380 feet above sea level; the 

 temperature, maximum, 120° ; minimum, 26° ; average annual rain- 

 fall on the irrigable lands, 17 inches. The duty of water is 3 to 3-J- 

 acre-feet per annum. The watershed area is 790 square miles. The 



